Development and improvement of methods of ozone therapy is closely related to the optimization of the technical tools providing solutions to a variety of clinical applications. Aim: The aim of this research is to develop a new method of extracorporeal ozonation and oxygenation of large volumes of blood, as well as the development of a new type of “ozone – blood” contactor. Materials and methods: The kinetics of the interaction of ozone with whole blood was studied by the "stopped flow" method using a continuous-flow cell. The cell was a rectangular tube formed by parallel glass plates. The cell was located strictly horizontally, filled with the whole blood of the volunteer and thermostated at 37 °C. Ozone-oxygen mixture was blown through the slotted hole along the cell at a controlled velocity. The concentration of ozone was measured with a flow-through photometric analyzer. Results: A comparative analysis of ozone therapy techniques has allowed to develop a new method of extracorporeal ozonation and oxygenation of large volumes of blood. The study of the chemical reaction kinetics of whole blood interaction with the ozone-oxygen mixture made it possible to construct a mathematical model describing the process of the heterophase reaction of ozone-blood interaction in a rotor-film contactor. An experimental copy of the plant for extracorporeal treatment of large volumes of blood with ozone was developed based on the model. The experimental results obtained on the developed hardware-software system showed good correspondence with the theoretical model, thereby confirming the possibility of practical application of the proposed method.